Does direct impact of SST on short wind waves matter for scatterometry?

Scatterometer radar backscatter depends on the relationship linking surface stress and surface roughness. SST can alter the growth rate of centimeter‐scale waves through its impact on air and water density and water viscosity. This SST‐dependency has not been included in the standard Geophysical Model Functions. This study uses a radar imaging model to evaluate this SST‐dependence and compares the results to observations from QuikScat Ku‐band and ASCAT C‐band scatterometers. A SST correction could raise wind speeds by up to 0.2 ms −1 in the storm track region of the Southern Ocean for C‐band scatterometers. For the higher frequency Ku‐band scatterometers, a SST‐induced reduction up to 0.4 ms −1 is predicted south of 60°S, where SST is cold and winds are moderate.